1. Field of the Invention
This invention relates to the field of defining data of interest. In particular, the invention relates to techniques and tools for enabling non-programmers to define data of interest.
2. Description of the Related Art
The development of the World Wide Web (WWW) has created an explosion in available information resources. However, it has also created a need for programs, or tools, that enable users to locate information of interest.
Two primary types of tools are used to find information on the WWW: search engines and catalogs. Search engines operate by using a robot, or crawler, to request web pages and add the pages to an index. The search engine receives a word or phrase input from a user and returns matching pages from its index. One example of a search engine is Altavista, http://www.altavista.com/. Catalogs, on the other hand, are typically maintained by humans and are much smaller in scope. Like a library catalog, each web site is categorized, e.g. a toll-free directory might be categorized under Reference: Telephone Directories: 800 Directories: etc. One example of a catalog system is Yahoo!, http://www.yahoo.com/.
Neither type of system is designed to extract information from WWW sites. For example, if a user wants to find the closing price of a stock along with other information about the stock, neither a search engine nor a web catalog is suitable for this task. Similarly, for comparison price shopping, search engines and web catalogs are unable to extract the relevant information from web sites to offer these features.
Tools have been developed to support comparison price shopping on web sites such as Jango, operated by Excite Corporation, Redwood City, Calif., at http://www.jango.com, and Junglee, operated by Amazon.com, Seattle, Wash., at http://shoptheweb.amazon.com/. Unlike search engines and web catalogs, these products extract specific information from particular web sites based on a user request. These prior systems are limited because they require sophisticated programming knowledge to enable the comparison shopping program to extract information from each web site. Further, these systems can not easily be extended outside the realm of comparison shopping.
Accordingly, what is needed is a method for defining data of interest usable by non-programmers to enable the extraction of data of interest from web sites.